20f is around -6c...if it's getting that cold i'm sure the diesel up there has a winterizer. if you're in San Diego i'll give you a bottle of the stuff i use in our diesel truck it's good for -11 to -15 or so Celcius. your diesel will like very much YA

Update. Called Shell gas station in Big Bear and very nice gentlemen told me that they carry what thy call winter blend which contains additives that provide protection from diesel jellying up in extremmly cold temperatures. According to him we are safe until temperature drops down to maybe 10F. Happy Thanksgiving everybody!

Diesel #1 goes down generally to -40ºC/-40ºF before gelling, although technically, the ASTM D 975 specification for diesel 1-D S15 requires only that the fuel not gel until 6ºC above the 10th percentile monthly low temperature of the State where the fuel is sold.

This is the general diesel sub forum. I think he is in the right place, what's the big deal? Would be nice if more UK diesel owners participated here, we US diesel owners could benefit from your experiences.

True, but they are mostly 18d and 20d owners. Few N57 owners frequent there as there is the dedicated N57.
Be careful where you are going with that, I wouldn't want to take this thread further off topic.